This invention relates to a spring element adapted to affect a component in a form-locking and force-locking manner at a temperature which is different from an initial, normal temperature. When structural elements of different temperature-caused elongation are joined, changes of configuration occur as a result of temperature alterations. Such configurational changes result in losses in pretension (bias) and/or cause gaps. At cryogenic temperatures superconductive cables and superconductive coils have to be installed such that their insulation is in a force-transmitting relationship with the support structure (such as a housing) in order to prevent displacements of the conductor which could cause a transition into the normal conductive state. In such an arrangement forces or pressures may be generated which, for example, in a toroidal magnetic field, may have an order of magnitude of 2.times.10.sup.6 Newton as well as forces due to an asymmetrical operation and forces generated by an approximately 1.5 mm expansion of the coil in the radial direction. This means that the forces thus generated have to be taken up in a positive force-transmitting manner by the coil housing at operating temperatures of 4.2 K. If this is achieved by preventing the coil housing from shrinking, stresses in the coil housing are generated, since the temperature-caused contraction of the coil housing would have to be greater or at the most as great as that of the coil assembly. In practice these values cannot be coordinated with one another in an arbitrary manner. In case of quenching (that is, transition into the normal conductive state), the inner pressure of the helium may amount to 25 bar. Since the thin-walled conductor shell is not capable of taking up the inner pressure, the outer layers of the coil winding must be supported on all sides by the coil housing.
The required firm support of superconductive cables or superconductive coils in a structure (such as, for example, an aluminum or stainless steel housing) is rendered more diffficult due to the different temperature-caused contraction of the winding and the housing. In case of large superconducting coils for example those for fusion applications, gaps in the order of magnitude of 200 .mu. are to be expected at a cooling from T=293 K. to T=4.2 K.
The above-outlined problem has been only partially resolved heretofore. The structural solutions attempted were all found to have disadvantages: they require a large structural length for the compensation of the different degrees of heat expansion whereby stability problems occur and a narrow construction is not feasible. On the other hand, a greater spatial requirement in the height direction is necessary, the friction is substantial, a bias (pretension) cannot be set and further, the permissible compression stress in the direction of reinforcement will be less than in a direction perpendicular to the reinforcement.